snapshot of https://github.com/blevesearch/bleve.git (master, 2026-09-15; blobs > 131072B omitted)

analysis/datetime/sanitized/sanitized.go

@@ -0,0 +1,130 @@
+//  Copyright (c) 2023 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sanitized
+
+import (
+	"fmt"
+	"regexp"
+	"time"
+
+	"github.com/blevesearch/bleve/v2/analysis"
+	"github.com/blevesearch/bleve/v2/registry"
+)
+
+const Name = "sanitizedgo"
+
+var validMagicNumbers = map[string]struct{}{
+	"2006":    {},
+	"06":      {}, // Year
+	"01":      {},
+	"1":       {},
+	"_1":      {},
+	"January": {},
+	"Jan":     {}, // Month
+	"02":      {},
+	"2":       {},
+	"_2":      {},
+	"__2":     {},
+	"002":     {},
+	"Monday":  {},
+	"Mon":     {}, // Day
+	"15":      {},
+	"3":       {},
+	"03":      {}, // Hour
+	"4":       {},
+	"04":      {}, // Minute
+	"5":       {},
+	"05":      {}, // Second
+	"0700":    {},
+	"070000":  {},
+	"07":      {},
+	"00":      {},
+	"":        {},
+}
+
+var layoutSplitRegex = regexp.MustCompile("[\\+\\-= :T,Z\\.<>;\\?!`~@#$%\\^&\\*|'\"\\(\\){}\\[\\]/\\\\]")
+
+var layoutStripRegex = regexp.MustCompile(`PM|pm|\.9+|\.0+|MST`)
+
+type DateTimeParser struct {
+	layouts []string
+}
+
+func New(layouts []string) *DateTimeParser {
+	return &DateTimeParser{
+		layouts: layouts,
+	}
+}
+
+func (p *DateTimeParser) ParseDateTime(input string) (time.Time, string, error) {
+	for _, layout := range p.layouts {
+		rv, err := time.Parse(layout, input)
+		if err == nil {
+			return rv, layout, nil
+		}
+	}
+	return time.Time{}, "", analysis.ErrInvalidDateTime
+}
+
+// date time layouts must be a combination of constants specified in golang time package
+// https://pkg.go.dev/time#pkg-constants
+// this validation verifies that only these constants are used in the custom layout
+// for compatibility with the golang time package
+func validateLayout(layout string) bool {
+	// first we strip out commonly used constants
+	// such as "PM" which can be present in the layout
+	// right after a time component, e.g. 03:04PM;
+	// because regex split cannot separate "03:04PM" into
+	// "03:04" and "PM". We also strip out ".9+" and ".0+"
+	// which represent fractional seconds.
+	layout = layoutStripRegex.ReplaceAllString(layout, "")
+	// then we split the layout by non-constant characters
+	// which is a regex and verify that each split is a valid magic number
+	split := layoutSplitRegex.Split(layout, -1)
+	for i := range split {
+		_, found := validMagicNumbers[split[i]]
+		if !found {
+			return false
+		}
+	}
+	return true
+}
+
+func DateTimeParserConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.DateTimeParser, error) {
+	layouts, ok := config["layouts"].([]interface{})
+	if !ok {
+		return nil, fmt.Errorf("must specify layouts")
+	}
+	var layoutStrs []string
+	for _, layout := range layouts {
+		layoutStr, ok := layout.(string)
+		if ok {
+			if !validateLayout(layoutStr) {
+				return nil, fmt.Errorf("invalid datetime parser layout: %s,"+
+					" please refer to https://pkg.go.dev/time#pkg-constants for supported"+
+					" layouts", layoutStr)
+			}
+			layoutStrs = append(layoutStrs, layoutStr)
+		}
+	}
+	return New(layoutStrs), nil
+}
+
+func init() {
+	err := registry.RegisterDateTimeParser(Name, DateTimeParserConstructor)
+	if err != nil {
+		panic(err)
+	}
+}